Cooling system for piston engines



L. BIRKIGT Feb. 13, 1940.

, 5 spets-sheei 1 wais IIIHINHI Filed Dec. 28, 1938 M flaw??? (ya Feb. 13. 1940. v L. BIRKIGT 2,190,394

COOLING SYSTEM FOR PISTON ENGINES Filed-Dec. 28, 1938 5 Sheets-Sheet 2 Feb. 13, 1940. L. BlRKlGT COOLING SYSTEM FOR PISTON ENGINES Filed Dec.

28, 1938 5 Sheets-Sheet 3 WTI H IHI I HI I l 1 J'ave'nwr:

Zozazis law/2 Feb. 13, 1940. L. BIRKIGT COOLING SYSTEM FOR PISTON ENGINES Filed Dec. 28, 1938 5 Sheets-Sheet 4 Feb. 13, 1940.

- L BIRKIGT COOLING SYSTEM FOR PISTON ENGINES Filed Dec;

28, 1.938 5 Sheets-Sheet 5 Pas el Fol 3. 13, 1940 v COOLING SYSTEM. FOR PISTON ENGINES Louis Birkigt, Versoii:, near Geneva, Switzerand Application December 28, 1938, Serial No. 248,131

,InBelgium February 11, 1938 17 Claims. (or 123-173 The present invention relates to machines of moved, of the cylinder head of an internal com the piston type which are to be provided" with bustion engine provided with a cooling system 1 coolingsystems. The invention is more espemade according to an embodiment of the inveng. cially, although not 'exclusively,concerned with tio'n;

machines of thiskind whichconstitute internal Fig. 2 is an end view of the same cylinder head combustion engines. I v i seen from the rear; 7 l v l I The chiefobject of the invention is to provide Fig. 3Iis an end view of the same cylinder head a machine of'this type which is better'adapted seen fromthe front; to meet the requirements of practice. 7 V Fig. 41s a longitudinal vertical section on the According to an essential'feature of, the presline IV-lV of Fig. 2; l '4, ent invention, in order to constitute the cooling Fig. 5 is a horizontal section on the line V--V means with which the machine is to'be provided, of Fig. 4; I I provide, in the c linder head of said machine, Fig. 6 is a longitudinal vertical section on the conduits(thisexpression designating in this case line VI-.-VI oiFig. 5; v I any recess through which'a'fluid' can'flow), at Fig. '7 is a transverse vertical section on: the v least one of which is forthe'circulation of a cool line VIl-VII of Fig. 5; v

ing'fiuid and at least one for the circulation of Fig. 8 is a transverse vertical section on the air. In a preferredembodiment of my invention, line VIII-N111 of Fig. 5; I a the last mentioned conduit (for the flow of air) Fig. 9 is a horizontal section on-the' line IX-IX isjlocated close to the Walls along which-circuof Fig. 8; i

late the fresh gases entering said machine. Fig. 1011s a horizontal section on the line X-.X i According to anotherfeature of the present of Fig. 8. l v i I, inventiomI provide, for constituting the cooling The following detailed description with refermeans .of the engine, in the walls thereof that once to the drawings relates to the case of anv a are to be cooled and especially in the cylinder internal combustion provided with a cooling sysheads, at least two clrculations of water or. antern according to the invention.

other-fluid, said two circulations being distinct Concerning first the general structure of the from each other at leastover a' portion of their engine, excepting the cooling system with which circuit. v I it is to be provided, it can bemade inany suit- According toa third feature of the present able conventional manner, including for instance 1 invention, in order to constitute the coollng a number n of cylinders E arranged in line or' v means'with which the engine is to be fitted, I torming several banks, forming for example a- I provide conduits for the passageof a'cooling fluid V, a Y, a w, or any other arrangement. in thewalls to be cooled, and in particular in By way of. example, the cylinders are constithe partitions extending between two adjacent tuted as shown Fig. 4 by tubular elements adapt- 35 cylinders, and the fluid circulation issoarrangecl ed tofibe screwed, through their ends adjoining that said fluid is compelled to move in at'le'ast the combustion chamber, and with the inter- 'theconduits which are provided. in saidparti position of "a packing memberz, on a cylinder tions. head 3, preferably common to all the cylinders 4c. According to still anoth e r'feature. of the pres of one bank. Preferably, as shown by the draw- 40 ent invention, thecooling system with which the ings, each of said cylinders is provided with two engine is to be fitted includes a casingsurroundinlet valves 4 and two exhaust valves 5, housed ing the intermediate and lower portions of the in'said cylinder head, respectively on opposite cylinders, said casingbeing provided with holes sides of the plane ofsymmetry of said'cylinder 16 so that air can circulate therein so as 'to' .cool head,.said valves being operated by means'of an said cylinders. Advantageously, this casing is overheadcam-shaft.

n e with the cylinderheadl Finally, I advantageously provide, for each Other features of the present invention will recylinder, two spark plugs which are carried by; sult from the following detailed description f bosses b provided in said cylinder at he oppo- .somespecific embodimentsthereof. 1 site. ends of a diameter thereof, and located re- Preferredj embodiments of the present inven spectively near the inlet valves d and the exhaust tion will be'hereinafter described with reference valves 5. I I 4 to the accompanying drawings, given merely "by Concerning now the cooling system which con-f way of example, and in which: 'stitutes the object of the invention, it is consti- Fig. 1 is an elevational view, with parts re ,tuted, according to a chiefreature of said inven- 1 j tion, by providing, in cylinder head 3, conduits some of which serve for the circulation of a cooling fluid, and the others for the circulation of air.

. Preferably, the conduits serving for the circulation of air (and which, on the drawings, are designated by letter A, either with an index or not) are located, at least chiefly, on the-same side of the longitudinal plane of symmetry of the cylinder head as the inlet valves 4, that is to say in the part of the cylinder head which is less liable to grow very hot due to the fact that the fresh gases fed to the cylinders flow along said part thereof.

As for the conduits which are to constitute the liquid cooling circuit, they are more particularly provided in the hot portions of cylinder head 3. Preferably, according to another feature of the invention,'these last mentioned conduits are arranged to form at least two circulations of liquid, which are distinct over at least a portion of their circuits.

7 It will be readily understood that such an arrangement of the cooling conduits of the engine" permits, while ensuring a thorough cooling of all the parts of the engine, of accelerating one of these circulations of liquid, so as more intensively to cool some portions of the cylinder head without having, for this reason, to accelerate the circulation of the whole of. the liquid flowing advantageous to have recourse to the specific arrangement illustrated by the drawings.

According to this embodiment of my invention the liquid circuits include respectively, inthe partitions'fi which extend between two adjacent combustion chambers, conduits B3 and -B'3 through which the liquid is compelled to circulate which permits, in particular, through a suitable choice of the cross sections of said conduits, of

accelerating said circulation of the liquid.

In order better to dislose the distribution and forms which have been found to be especially advantageous for the various elements of the structure, and in particular circuits A, B and B", the

drawings give the relative proportions of said elements.

Furthermore, in order to simplify these drawings, I have shown, in some figures, only the front and rear parts of cylinder head 3, which 1 are the only elements to have certain different characteristics, these parts being connected by n-2 intermediate parts which are similar to one another and include elements common with the I end parts. i

It will be readily understood that, according as the engine that is considered is provided with a tractive airscrew or a pusher airscrew, the

I front part of the engine that is considered separately is turned toward the front or toward the rear of the aircraft. In the drawings, it has been assumed that the Ian-screw associated with the engine served to pull the aircraft. but in the embodiment of my.

invention which will now be described more inengine.

Concerning first. the aircircuit A, it is consti tuted in such manner that air penetrates into. f the front part of the cylinder, head through a 1 lateral inlet conduit A1, then flows along the escapes through a conduit A2 which would,IJon the contrary, play the part of inlet conduit in the case of an engine associated with a pusher airscrew. 1

- detail, the whole is arrangedin such manner tha t I the various inlets or outlets of fluidcan be turned indifferently toward one end or the other of the.

walls surrounding'the inlet valves 4 andfinally 15 I Concerning now the liquid circuit B, it includes an inlet conduit B1 (disposed laterally on the side opposed to conduit A1 with reference to the!- longitudinal plane of symmetry) which runs over the whole length of the cylinder head. and the front end of which is preferably closed by a, plug 7 (said end being used for the inflow of the liquid,

in the case of an engine associated with a pusher airscrew) This conduit B1 communicates, opposite the partitions existing between two adjacent cylinders, with conduits B3 provided 'in said parti-;, f

tions, through the medium of COIIdUitSBz each of which communicates with the whole of the conduits B; corresponding to thesame partition.

rangement and number. For instance, I provide three conduits B3 for each partition.

Said conduits B3 open intoa jacket or chamber B4 which partly surrounds the exhaust valves '5 and extends in the direction of the bosses b which carry the spark plugs provided near ,the' inlet valves 4. Thisjacket Bi'may even wholly sur- Jacket Bi'is provided, nea1 the front and rear ends of the cylinder head round said #bosses,

structured, with'outlet conduitsBs, one OfnWhiCh.

tioned conduits. l M

It will be readily understood that, with such through conduits B3 since said conduits are arranged in series in the cooling circuit which starts,

from the inlet conduit B1 and leads to the outlet conduit B5.

It should be noted that, advantageously, circuit B should be completed by connecting-.con-

These conduits B3 may be of any particular ar may be closed, the, outflow of. the liquid; then 1' I taking place through the other of said last menl 5 a circuit, liquid will'be compelled to circulate duit B1 to jacket B4 through conduits B5 passing" 1' between the valves of each cylinder. .These con-' duits B6 produce but a slight reduction of the;

circulation of liquid through conduits B3.

1- will now consider the arrangement of the other liquid circulation system, to wit B.

This system includes an inlet conduit B'1 pro vided, in a manner similar. to conduit B1, on one sideof the cylinder head and, preferably, under.

said conduit.B1

This conduit B71 is connected, through the medium of conduits B z,'.with conduits B'c'pro v vided in partitions 6 under conduits B3, and lo cated, for instance-at the level of the cylinder] heads. I may, by way of example, provide one conduit B's in each partition 6.

, I connect the outlet, end of each conduit 'B'a,

for instance, through the intermediate of two conduits B'4, formin a V, with the jacket Biof circuit B, the evacuation of the liquid from cir-' cuit B' then taking place through conduits B5 which, in this case, arecommon. same as jacket B4, to circuits B and B.

a plurality of cylinders forming at least one bank of cylinders, and pistons movable in said cylinders, respectively, a head common to all of said cylinders, inlet valves for said cylinders located in said head all on one side of the middle plane to said exhaust valves, said circuit including pas sages extending to the other side of said plane so as to pass near the bosses corresponding to the inlet valves.

9. In an internal combustion engine including a plurality oi cylinders forming at least one bank of cylinders, and pistons movable in said cylinders, respectively, a headcommon to all of said cylinders, inlet valves for said cylinders located said head all on one side of the middle plane of said bank of cylinders, exhaust valves for-said cylinders located in said head all on the. other side of saidv middle plane, ignition plug supporting bosses carried by said cylinders near said inlet and exhaust valves respectively, at least one air cooling circuit formed in said head, including a main passage running longitudinally of said bank of cylinders on the side of said middle plane thereof corresponding to the inlet valves, and at least two distinct liquid cooling circuits formed in said head, including each a main conduit running longitudinally of saidbank of cylinders on the side'of the middle plane of said bankcorresponding to the exhaust valves, at least one of the two last mentioned circuits including passages extending to the other side of said plane so as to pass near the bosses corresponding to the inlet valves. l

10. In an internal combustion engine including a plurality of cylinders forming at least-one bank of cylinders, and pistonsv movable in said cylinders, respectively, a head common to all of said cylinders, partitions betweensaid cylinders carried by said head, inlet valves for said cylinders located in said head all on one'side of the middle plane'of said bank of cylinders, exhaust valves eluding a main conduit runnin longitudinally oi said bank of cylinders on the side of t is middle plane of said bank corresponding tothe exhaust valves, at least one conduit in series with said liquid circuit provided in each of said partitions, said last mentioned circuit including passages extending to the other side of said plane so as to pass near the bosses corresponding to the inlet valves. 1

11. In an internal combustionengine including a plurality of cylinders forming at least one bank of cylinders, and pistons movable in said cylinders, respectively, a head common to all of said valves of each cylinder.

' for said cylinders located in said head, exhaust head, at. least one air cooling circuit, formed in,

valves, at least one of said liquid cooling circuits arodso r cylinders, inlet valves for said cylinders located in said head all on one side oithe middle plane of said bank of cylinders, exhaust valves for said cylinders located in said head allxon'the Othel. side of said middle plane, at least one air; cooling 5? circuit formed in said head, including a main -pas'-; sage runninglongitudinally of said bank of cylin--. ders on the'side of the middle plane thereof cor 3 responding to the inlet valves, and at least, one liquid cooling circuit in, said head'includinga main passage running longitudinally of said bank of cylinders on the side of the middle plane of said bank corresponding to the exhaust valves,:-

two longitudinal passages being, adaptedto be closed at will at eitherof their ends. Y 12. In an internal combustion engine including a plurality of cylinders forming at least one bank 5 of cylinders, and pistons movable in said'cylin ders, respectively, ahead common to all of said cylinders, inlet valves for said cylinders located v in said head all on one side of the middle plane of said bank of cylinders, two exhaust valves for, I

each of said cylinders, all ofsaid exhaust valves being located on the other side of saidmiddle; plane of the bank of cylinders, 'atlast one air cooling circuit formed in said head especially adapted to cool said inlet valves, and at least one liquid cooling circuit formedv in said head ar-$ ranged especially to cool said exhaust valves,=ijnf. cluding'conduits passing between thetvvo exhaust "3,0,:-

13. In an internal combustion-engine including" i: plurality of cylinders forming at least one (bank; of cylinders, and pistons movable in: said cylin-j ders, respectively, a head common to'all of said I v v cylinders, inlet valves for said cylinderslocated in said head, outlet valves for said""cyli nders".,- located in said head, at least one air cooling air cuit formed in said head especially adapted to cool said inlet valves, two liquid cooling circuitsa) formed in said head adapted especially-. to cool;

said exhaust valves, and a common return" pasvalves for said cylinders located in saidheadqat least one air cooling circuit formed in said head especially adapted to cool said inlet valves,-and at I least one liquid cooling circuit-formed in -said. head arranged especially to coolsaid exhaust 55 valves, including 11 series conduits provided in said partitions. I 15. In an internal. combustionlengine including a pluralityof cylinders, pistonsmovable in said cylinders, respectively, the combination, oi .a; head common to all of said cylindersforming. partitions between two adja'ceritcylinders, inlet 5 valves for said cylinders located in said head, exhaust valves for said cylinders located said- 65" said head especially adapted (to cool 'saidinlet valves, two liquid coolingcircuits formedin said head especially adapted to cool said exhaust including in series conduits provided in said para 70 titions, and'a common return passage for both 3 of said liquid cooling circuits. I 16. In an internal combustion engine including a plurality of cylinders, pistons movable in said" cylinders, respectively, thecon bination of a head 16;

common to all of said cylinders, inlet valves ior said cylinders located in said head, exhaust valves for said cylinders located in said head, at least one air cooling circuit in said head and one liquid cooling circuit in said head, and one casing supported 'by said head surrounding said cylinders, provided with holes for the passage of air therethrough.

. 17. In an internal combustion engine including.

a plurality of cylinders forming at least one bank, pistons movable in said cylinders and inlet and exhaust valves for said cylinders, a head common to said cylinders, at least one air cooling circuit side corresponding to said inletvalves in direct heat exchange relation with the cooler parts ofl.

the cylinder Walls, and at least oneliquid cooling walls.

formed in said head and including a main conduit running along said bank of cylinders on the LOUIS BIRKiGT. 

